It's been cold and wet here in New England (video)

I know Chickens don't catch colds like we do but this girl is surely congested and I think it's related to the weather. She is currently in my basement taking up residence in the "hospital pen". She seems fine, isn't lethargic but her crop is empty and she feels a little thin to me (but all my silkies have been broody all summer and fall). She's about 8 months old. None of the other birds have any signs of this. She shares housing with 26 guinea fowl( free range during the day), 3 orpington hens, a pair of leghorns (Frank & Dixie) and 10 other silkies. Any suggestions on how I can make her feel better would be great. . She sneezes around the 47 second mark on the video. Sorry it's poor quality.